Optical systems with positionable optical devices, such as light sources, are generally well known. These devices, which have a wide variety of uses, typically include an optical device that serves as a source of radiation, such as an arc lamp. The proper performance of such optical systems depends, in large part, on the accurate positioning of the various optical devices of the system, such as, for example, the lamp that supplies the radiation, and a focal lens, which focuses and transmits this radiation to an object to be illuminated or otherwise receives the radiation, as well as any other desired optical components, such as mirrors or condensers.
Accordingly, mechanisms for positioning at least one optical device relative to another have long been employed in such systems, such as, for example, those disclosed in U.S. Pat. No. 3,436,050 to Tibbals, U.S. Pat. No. 4,712,444 to Lewis, and U.S. Pat. No. 5,136,433 to Durell. Typically, such mechanisms include the ability to adjust the horizontal and vertical orientation of an optical device. However, these designs generally only permit adjustments in these two axes (i.e., the X and Y axes). Therefore, while these arrangements allow the user to obtain a particular alignment between optical devices, they do not permit adjustment of the distance between them, which would otherwise provide a focusing movement generally important in optical systems.
Accordingly, it has been suggested to use a positioning device that is able to move an optical device in three orthogonal directions, such as the design described in U.S. Pat. No. 4,840,450 to Jones et al. This type of system allows the position of an optical device to be manually adjusted along the X, Y, and Z axes using three mutually orthogonal adjustment rods. However, these known systems have a number of disadvantages, including arrangements that involve multiple, complex parts, which are typically expensive and difficult to manufacture, such as the assembly of micropositioning devices described in the '450 patent, as well as the undesirable effect that repositioning along one axis has on the adjustments that have been made along the other axes.
Additionally, another problem with such systems is that often, it is advantageous to have a device such as a cooling fan as part of the system, particular when dealing with radiation generating devices and their power supplies. However, this fan, which is typically mounted to whatever housing houses the optical system, generates undesirable vibrations. As a result, the various parts of the system, including the optical devices and the positioning devices therefor, likewise experience this vibration. This vibration of the optical devices can cause slight misalignments during use of the system, and vibration of the positioning device during adjustment can result in imprecise alignment of these optical devices in the first place.
What is desired, therefore, is optical system that allows efficient adjustment of the optical devices in three orthogonal directions. What is further desired is a system that reduces the amount of vibrations experienced by the system. What is also desired is a system that achieves the above objectives that can be manufactured with simple, inexpensive parts.